如何使用java代码加载指定包下面的所有类

如何加载指定包下面的所有类

使用代码来实现加载指定包下面的所有类

配置文件config.properties（其位置在resource目录下）

page=cn.ishow

读取配置文件工具类

/**
* 读取配置文件工具类
*/
public abstract class ReadUtils {
private static Map<String,Object> cache = new HashMap<>();

private static Properties properties = null;

static {
properties = new Properties();
try {
properties.load(ReadUtils.class.getResourceAsStream("/config.properties"));
} catch (IOException e) {
e.printStackTrace();
}
}

public static Object read(String key){
Object value = cache.get(key);
if(value==null){
synchronized (ReadUtils.class){
value = cache.get(key);
if(value==null) {
value = properties.get(key);
cache.put(key, value);
}
}
}
return value;
}

}

主要类

package cn.ishow.manage.test;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class LoadPageClassTest {

/**
* 解析包的全路径(比你的包路径为cn.ishow.test)
* @param webPackage
* @return
*/
public String resovlePackagePath(String webPackage) {
// 扫码所有的包并把其放入到访问关系和方法放入到内存中
File f = new File(getClass().getResource("/").getPath());
String totalPath = f.getAbsolutePath();
System.out.println(totalPath);
String pageName = getClass().getPackage().getName().replace(".", "\\");
totalPath = totalPath.replace(pageName, "");
String packagePath = webPackage.replace(".", "\\");
totalPath = totalPath + "\\" + packagePath;
return totalPath;
}

/**
* 解析包下面的所有类
* @param packagePath 上一步获取包的全路径
* @param webPackage  包(cn.ishow.test)
* @return
*/
public List<String> parseClassName(String packagePath, String webPackage) {
List<String> array = new ArrayList<>();
File root = new File(packagePath);
resolveFile(root, webPackage, array);
return array;

}

private void resolveFile(File root, String webPackage, List<String> classNames) {
if (!root.exists())
return;
File[] childs = root.listFiles();
if (childs != null && childs.length > 0) {
for (File child : childs) {
if (child.isDirectory()) {
String parentPath = child.getParent();
String childPath = child.getAbsolutePath();
String temp = childPath.replace(parentPath, "");
temp = temp.replace("\\", "");
resolveFile(child, webPackage + "." + temp, classNames);
} else {
String fileName = child.getName();
if (fileName.endsWith(".class")) {
String name = fileName.replace(".class", "");
String className = webPackage + "." + name;
classNames.add(className);
}
}
}
}
}

public static void main(String[] args) {
LoadPageClassTest test = new LoadPageClassTest();
String packageData = (String) ReadUtils.read("page");
String totalPath = test.resovlePackagePath(packageData);
System.out.println(packageData +"   "+totalPath);
List<String> datas = test.parseClassName(totalPath,packageData);
System.out.println(datas);
}

}

结果

[cn.ishow.manage.mapper.ITestEntityMapper, cn.ishow.manage.mongo.dao.IBaseDao, cn.ishow.manage.mongo.dao.impl.BaseDaoImpl, cn.ishow.manage.mongo.dao.impl.TestBeanDaoImpl, cn.ishow.manage.mongo.dao.impl.UserBeanDaoImpl, cn.ishow.manage.mongo.dao.ITestBeanDao, cn.ishow.manage.mongo.dao.IUserBeanDao, cn.ishow.manage.redis.RedisCache, cn.ishow.manage.service.impl.TestBeanServiceImpl, cn.ishow.manage.service.impl.TestEntityServiceImpl, cn.ishow.manage.service.impl.UserBeanServiceImpl, cn.ishow.manage.test.LoadPageClassTest, cn.ishow.manage.test.ReadUtils, cn.ishow.manage.weixing.WeiXingUtils]

有了这些类全名称，我们就可以利用反射获取该类，并进行一系列操作。由于本人有点忙，很多人用csdn提问我都没回，如果有问题qq发消息本人qq863224759。下篇将写本人简单模拟springmvc的实现